Sound motion picture apparatus



March 25, 1941. A. e. ZIMMERMAN 2,235,972

SOUND MOTION PICTURE APPARATUS Filed June 25. 1938 Bntmntor attorney Patented Mar. 25, 1941 rrso STATES SOUND MOTION PICTURE APPATUS Arthur G. Zimmerman, Indianapolis, ms, t

or to Radio Corporation of America, a coration of Delaware Application June 25, 1938, Serial No. 215365 1 Claim.

drive for such apparatus.

Both motor and gear drives have been customary in conjunction with such apparatus in the prior art but they have often required a complicated and expensive filter mechanism to absorb the irregularities imparted to the apparatus from the motor and drive mechanism.

in the apparatus according to the present invention, a belt drive from the motor is provided and the motor mounting is so constructed that large irregularities may be absorbed by bodily movement of the motor, while smaller irregularities may be absorbed by the rubber. mounting in which the motor is supported.

who object of the invention is to provide an improved motor support for sound motion picture amiaiatus.

another object of the invention is to provide an improved shock-absorbing means for the drive of such apparatus.

another object of the invention is to provide belt-tensioning means for such apparatus.

other object of the invention is to provide means for absorbing slight irregularities in the operation of the motor driving such apparatus.

Other and incidental objects of the invention will be apparent to thoseskilled in the art from a reading of the following specification and an inspection of the accompanying drawing, in which the single figure of drawing is an elevation of a motor mounting in accordance with my invention as applied to a. soundhead for motion picture apparatus. 1

in the apparatus as shown, the soundhead casinn is represented at it. This soundhead casing may be supported upon the usual type of pedestal and may support a motion picture projector of all] any desired typ but both of these features may i be omitted if it is desired to use thefapparatus only as a film phonograph. The soundhead may, if desired, be constructed substantially as shown and described in Loomis et a1. Patent 2,019,147 with the exception of the provision of a belt pulley or flywheel H for driving the soundhead and attendant mechanism instead of the gear drive provided in the Loomis 'et a1. construction. This pulley II may be driven by the belt or belts l2 which are preferably oi the V type and, in order to insure smooth operation, may be two or three in number. The belts I! are driven by an electric motor I3 which is'preferably of the synchronous type, although any substantially constantspeed motor maybe used. This motor is supported on a bracltet member generally indicated at ll and which in t a is hinged by a U-shaped bracket member it upon the pin i6 extending through the soundhead and secured therein by the set screw W. This motor i3 drives the sprocket it through the pulley ii and the belts it. The motion picture projector may, it de sired, be neared to the shaft carrying the sprochet it. The film lb, which is held in cooperative -'relation with the sprocket it by the pad rollers w ii, is drawn past a point in appropriate relation to the photocell it in a manner substantially as shown and described in the aforesaid lloomls et al. patent.

The motor it is supported on the bracket it M by two members it, one at each end of the mem her it, and these members tt have turned-up edce's it formed into a semi-circular shape and held toward h other by the bolt it. The motor i3 is provided at each end with a. cylindri- 30 cal extension it and around this extension lb T there is provided a rubber ring 2b which in turn is encased in a cylindrical metal member ll. This metal member ll is ly clamped-by the members it and the bolt to so that any rota- 2 tional movement of the motor in relation to the braclgzet it i necessarily absorbed by the rubber rings at. The bracket it is held toward the soundhead casinc it by a cap screw or bolt 2B, of which more than two may be provided, it de- 30 sired. This bolt is threaded into the soundhead casing as indicated and is prevented from rotation Itherein by a lock nut 29. This bolt is so adjusted as to leave the proper operating tension upon the belts H, which operating tension i us- 35. v

ually less than that which would be provided by the weight 01' the motor. It will be apparent from the construction thus far described that if any irregularity in one or more of the belts i2 passes over either the motor pulley 30 or the 40 main driving pulley ii, the tensiomupon the belts will be increased and will tend to move the bracket it toward the soundhead against the effect of the weight of the motor l3, thereby decreasing the effect of any such irregularity upon the rotational speed of the pulley ii. If the ten sion provided upon the belts I! by the weight of the motor I3 is not suflicieut, an auxiliary nut J 3| may be provided on the bolt 23 and a. suitable helical spring may be provided between this nut 3| and the rear face of the bracket l4, thereby. increasing the tension upon the belts to any desired amount.

Small irregularities in the rotational motion of the Pulley of the motor N or other small irregularities in the. belts it or either the pulley II or the pulley ill, which are of sumcient magnitude to react upon the rotor of the motor but which are insumcient to cause a littin: of the motor and the bracket It, will tend to cause the iremeoi the motor II to rotate a corresponding amount and any such rotational tendency will be absorbed by means of the circular rubber members 28. c

It will be apparent from the foregoing that I have provided a construction in which small and sudden or high-speed periodic vibrations will be absorbed by means of the rubber absorbing membeta 25, while larger vibrations or irregularities, either in the motion of the motor or due to the irregularities of the construction of the several members of the driving train, will be absorbed by bodily movement of the motor and its supporting bracket.

Having now described my invention, I claim:

A hanger for supportina an electric motor comprising a bracket secured to the motor at one side thereof, hinge means supporting said bracket adjacent the bottom or the motor, an adjustable rigid stop abutting said bracket adjacent the top thereof, for adjusting belt tension, and resilient means pressing said bracket toward said stop, whereby said bracket may move away from said stop against the weight 0! the motor and the pressure oi said resilient means. in response to excessive belt tension.

ARTHUR G. ZIMMER. 

